Cornell Lab of Ornithology, Cornell University, Ithaca, NY 14850, USA.
American Bird Conservancy, Washington, DC 20008, USA.
Science. 2019 Oct 4;366(6461):120-124. doi: 10.1126/science.aaw1313. Epub 2019 Sep 19.
Species extinctions have defined the global biodiversity crisis, but extinction begins with loss in abundance of individuals that can result in compositional and functional changes of ecosystems. Using multiple and independent monitoring networks, we report population losses across much of the North American avifauna over 48 years, including once-common species and from most biomes. Integration of range-wide population trajectories and size estimates indicates a net loss approaching 3 billion birds, or 29% of 1970 abundance. A continent-wide weather radar network also reveals a similarly steep decline in biomass passage of migrating birds over a recent 10-year period. This loss of bird abundance signals an urgent need to address threats to avert future avifaunal collapse and associated loss of ecosystem integrity, function, and services.
物种灭绝定义了全球生物多样性危机，但灭绝始于个体数量的减少，这可能导致生态系统的组成和功能发生变化。我们利用多个独立的监测网络，报告了 48 年来北美鸟类群落在大部分生物群落中的数量损失，其中包括曾经常见的物种。对区域范围的种群轨迹和规模估计进行整合表明，接近 30 亿只鸟类的净损失，即 1970 年鸟类数量的 29%。一个覆盖整个大陆的天气雷达网络也显示，在最近的 10 年期间，迁徙鸟类的生物量通过量同样急剧下降。鸟类数量的减少表明迫切需要解决威胁，以避免未来鸟类群的崩溃以及相关的生态系统完整性、功能和服务的丧失。
